Final answer:
Wickham realizes Elizabeth knows about his true relationship with Darcy because he avoids her and tries to leave town.
Step-by-step explanation:
The evidence that Wickham realizes Elizabeth knows all about his true relationship with Darcy is option B) Wickham avoids Elizabeth and tries to leave town.
This is shown in the passage where it describes Wickham's behavior as being expressed through stiffness of manner and resentful silence. This suggests that Wickham is aware of Elizabeth's knowledge and is trying to avoid any confrontation or further discussion about the matter.